This invention relates to solar energy power conversion systems. More particularly, this invention relates to reflective solar concentrator systems which support individual heat energy conversion units at their focal points. Still more particularly, this invention relates to improvements in the configuration of the supporting structure for such solar concentrator systems.
With the emphasis on alternative power sources to traditional fossil fuels, increasing attention has been paid in the last few years to solar power energy conversion systems. This invention is concerned generally with the conversion of solar heat energy into mechanical energy and then into electrical energy. One technique to this end has been to construct a large number of individual heliostats which reflect onto a central heat receiver through which commonly circulates some sort of liquid to which the heat energy reflected from the multiple heliostats is transferred at the centrally located heat collector point. This heated fluid is usually then conducted to some sort of turbine-electric power generator unit. An alternative strategy is to create a one-to-one correspondence between an individual heliostat and a heat energy converter. This is the basic thrust of the present invention. The standard configuration has been to locate a heat energy receiver/converter on a support structure which is attached to the periphery of the parabolic reflector such that the heat collector is located at the focus of the reflector. A base pedestal supports this heat collector/converter-support beam reflector subsystem. In prior art systems, the base pedestal has been located at the back side of the reflector. Other base support means have also been utilized besides a single pedestal; however, these other base supports have also been configured such that they are attached to the rear of the parabolic reflector. In any event, it is clear that the heat collector/converter-support beam reflector subsystem will act in almost all instances as a cantilevered load relative to the base support structure. As such, it places high loads upon the base support structure and the attached tracking drive motors necessary to accurately position the reflector subsystem relative to the changing position of the sun during the course of the day.
Apparently these prior art support configurations stem from the heritage of similar appearing radar dishes and the like. In such radar dishes, the power requirements of the tracking drive units are not a particularly significant criterion for the design of these radar dishes. However, in the design of a solar collector power energy conversion system, power efficiencies are critical to the economic success of the solar power conversion facility. Hence, these prior art designs for the solar concentrator systems have suffered from a relatively inefficient design which requires relatively high power tracking drive motors given the high loads that these designs place upon these motors.